1-(2-thenyl)-2-di-lower alkylaminoethyl diphenylacetate and related compounds



United States Patent This invention pertains to novel chemical compounds and a process for their preparation. More particularly, the invention pertains to 1-(2-thenyl)-2-aminoethyl esters of diphenylacetic acid. The compounds of the invention in the form of their free bases are represented by the following general structural formula )D wherein X is a halogen atom having an atomic weight from 35 to 80, n is an integer from 0 to 1, R and R taken separately represent lower-alkyl radicals, for example, methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, and isomeric forms thereof, and R and R taken together with -N represent a saturated heterocyclic radical containing from 5 to 7 atoms in the ring, one of which, in addition to the amino nitrogen, is selected from the group consisting of carbon, nitrogen, oxygen, and sulfur, the other ring atoms being carbon, for example, piperidino, 4-propylpiperidino, pyrrolidino, 2,2-dimethylpyrrolidino, hexamethyleneimino, 2-methylhexamethyleneimino, morpholino, 2-methylmorpholino, thiamorpholino, 4-methylpiperazino, and the like. The novel compounds of the invention also include the acid addition salts of the foregoing free base compounds.

In accordance with the process of the invention, the novel compounds represented by Formula I above are prepared by condensing metallo-thiophene (or a monochloro or monobromo substituted metallo-thiophene) with an N,

'N disubstituted-L3-epoxypropylamine to produce a l-(2- 'thenyl) -2-aminoethan0l having the following general structural formula wherein X, n, and R and R are as defined in Formula I, and reacting the I-(Z-thenyl)-2-arninoethanol thus formed with a diphenylacetylating agent, illustratively, diphenylacetyl halide (e.g., diphenylacetyl chloride).

Advantageously, the novel l-(2-thenyl)-2-aminoethanol intermediates of Formula II are obtained by an addition reaction beween a 2,3-epoxypropylamine of the kind noted above, illustratively, N-(2,3-epoxypropyl)diethylamine, N-(2,3-epoxypropyl)pyrrolidine, N-(2,3epoxypropyl)piperidine, N-(2,3-epoxypropyl)-N-methylhexylamine, N- (2,3-epoxypropyl)morpholine, N-(2,3-epoxypropyl)thiamorpholine, N-(2,3-epoxypropyl)-2,2-dimethylpyrrolidine, and the like, with Z-thienyllithium or a halo-Z-thienyllithrum.

The Z-thienyllithium or chloro(or bromo) -2-thienyllithium is prepared by reacting thiophene or chloroor bromosubstituted thiophenes with butyllithium according to the method of Gilman and Shirley, J.A.C.S. 71, 1870 (1949). Alternatively, S-chloro-Z-tliienyllithium can also be prepared by reacting 2,5-dichlorothiophene with butyllithium.

2,3-epoxypropylamines of the kind mentioned are obtained by known methods. For example, one can react an epihalohydrin such as epichlorohydrin with a secondary amine, for example, diethylamine, pyrrolidine, piperidine, N-methylhexylamine, morpholine, thiamorpholine, 2,2-dimethylpyrrolidine, and the like, to obtain a desired 2,3- epoxypropylamine.

The reaction of the 2,3-epoxypropylamine and a 2- thienyllithium is exothermic, and it is preferred to mix the reactants slowly and cautiously in the presence of an inert solvent. The reaction proceeds satisfactorily from about 0 C. to about 125 (3., preferably from about 25 C. to about C. Generally, the reaction can be readily controlled by slowly adding one of the reactants to -a solution of the other in an inert organic solvent, for example, ether, technical hexane (Skellysolve B'), and like solvents. Frequently, it is particularly convenient to adjust the rate of addition so as to maintain the reaction mixture at a gentle reflux. Advantageously, the 2,3-epoxypropylamine is added to a solution of a Z-thienyllithium, in which case it is convenient to utilize the reaction mixture obtained in the preparation of the Z-thienyllithium without separating and purifying the latter. After the reaction of the 2,3-epoxypropylamine and the Z-thienyllithium is completed, any lithium complexes that have been formed are decomposed by treating with water or a dilute aqueous acid, illustratively, 10% aqueous sulfuric acid, and the like. The resulting l-(Z-thenyl)-2-aminoethanol of Formula II is recovered and purified if so desired by con ventional methods known in the art, illustratively, by solvent extraction, vacuum distillation, etc.

The novel l-(Z-thenyl)-2-aminoethyl diphenylacetates of the invention are obtained by reacting a diphenylacetylating agent, preferably a diphenylacetyl halide (e.g., diphenylacetyl chloride) with a l-(Z-thenyD-Z-aminoethmol in thepresence of an inert organic solvent, for example, benzene, ether, toluene, tetrahydrofuran, and the like. An acid acceptor, for example, pyridine, triethylamine, and the like can be included in the reaction mixture in order to react with the hydrogen halide that is produced by the reaction. If an acid acceptor is not included, the compounds can be recovered in the form of their hydro halide acid addition salts, or they can be recovered in their free base form by neutralizing the reaction mixture with alkali and extracting the free base with an organic solvent, for example, ether.

The acid addition salts of the free bases (Formula I, above) are obtained by reacting said free bases with an acid, i-llustratively, pharmacologically acceptable acids, for example, hydrochloric, hydrobromic, sulfuric, phosphoric, sulfamic, acetic, lactic, tartaric, gluconic, citric, benzoic, salicylic, and like acids.

The novel l-(l-thenyl)-2-aminoethyl diphenylacetates of this invention, in free base form or in the form of acid addition salts with pharmacologically acceptable acids, possess valuable pharmacological activity. Illustratively, the compounds of the invention are drug potentiators and tranquilizing agents. Thus they can be used to prolong the activity of anesthetics, analgetics, sedatives and hypnotics. More particularly, the compounds are useful for prolonging hexobarbital-induced sleep in mammals. For example, the effectiveness of l-(2-thenyl)-2- diethylaminoethyl diphenylacetate hydrochloride in prolonging hexobarbital-induced sleep is illustrated in Table I. Test mice weighing 20 to 25 g. each were given various dosages of 1-(2-thenyl)-2-diethylaminoethyl diphenylacetate hydrochloride. After the designated interval (30 minutes to 120 minutes), each received, intraperitoneally, 100 mg./kg. of hexobarbital sodium. The subsequent duration of sleep was recorded, and the results are presented as an average prolongation (in percent) over the sleep duration of control mice receiving only hexobarbital sodium at 100 mg./kg. There were six mice in each group.

1 LDso, 650 mgJkg.

The compounds have a very low atropine index [for example, 1-(2-thenyl)-2-diethylaminoethyl diphenylacetate hydrochloride has an atropine index of 1/ 100], and therefore they cause no substantial anticholinergic side-etfects such as dryness of the mouth, blurring of vision, constipation, tachycardia, etc.

Furthermore, the compounds of the invention are useful, in accordance with U.S. Patents 1,915,334 and 2,075,359, in forming amine fluosilicate mothproofing agents, and in accordance with US. Patents 2,425,320 and 2,606,155, in forming amine thiocyanate-formaldehyde condensation products for use as pickling inhibitors.

When used in therapy, the novel compounds of the invention, in the free base form or in the form of acid addition salts with pharmacologically acceptable acids, can be combined with solid or liquid pharmaceutical carriers and formulated in the form of tablets, powder packets, or capsules, using starch and like excipients, or dissolved or suspended in suitable solvents or vehicles for oral or parenteral administration.

The following examples are illustrative of the process and products of the present invention but are not to be construed as limiting.

Example 1.-Preparation of J-(Z-Thenyl)-2-Diethylaminoethyl Diphenylacetate Hydrochloride PART A.PREPARATION or 1-(2-THENYL)-2-DIETHYL- AIVIINOETHANOL To an ether solution containing 0.43 mole of butyllithium was added 50.4 g. (0.6 mole) of redistilled thiophene in 50 ml. of ether. After stirring at room temperature for /2 hour, the reaction mixture was heated and stirred at reflux temperature for 3 hours, whereupon 78 g. (0.6 mole) of N-(2,3-epoxypropyl)diethylamine in 75 ml. of ether was added dropwise. The heat of reaction was sufficient to maintain the mixture at reflux temperature. When the reaction was completed (evidenced by a negative test for the starting organolithium compound), the addition complex thus obtained was hydrolyzed by adding cold aqueous sulfuric acid. The acidhfied reaction mixture separated into two layers, and the ether layer was extracted with several portions of 10% aqueous sulfuric acid. The original acid layer and the acid extracts were combined, neutralized with 40% aqueous sodium hydroxide, and extracted with ether, and the ether extract was dried over anhydrous potassium carbonate. The dry ether solution was filtered and distilled, with the 1-(2-thenyl)-2-diethylaminoethanol being collected at a boiling point of 121 to 122 C. at 6 mm. mercury pressure. The product weighed 65 g. (71%); its density (D was 1.0226 and its refractive index (n was 1.5106.

Analysis. Calculated for C H NOS: N, 6.56. Found: N, 6.54, 6.36.

PART B.PREPARATION OF 1-(2-THENYL)-2-DIETHYL- AMINOETHYL DIPHENYLACETAT'E HXTJROICHLORIDE Amixture of 5.4 g. (0.025 mole) of 1-(2-thenyl)-2- diethylaminoethanol (Part A) and 5.5 g. (0.025 mole) of diphenylacetyl chloride in 50 ml. of benzene Was refluxed for 2 hours. The benzene was removed by distillation, and the residue was recrystallized from ethyl acetate. There was thus obtained 9.5 g. (86%) of solid 1-(2- thenyl)-2-diethylarninoethyl diphenylacetate hydrochloride. After another recrystallization from ethyl acetate the compound had a melting point of 139.5 to 140.5 C. and gave the following analysis:

Calculated for C H CINO S: C, 67.62; H, 6.81; N, 3.16; Cl, 7.98; S, 7.21. Found: C, 67.62; H, 6.63; N, 3.36; Cl, 8.14; S, 7.16.

Example 2.Preparation of I-(Z-Thenyl)-2-Diethylaminoethyl Diphenylacetale and Hydrochloride Thereof 1200 g. (5.6 moles) of I-(Z-thenyl)-2-diethylaminoethanol and 1355 g. (5.9 moles) of diphenylacetyl chloride were mixed in 6 l. of benzene, and heated under reflux for 3 hours. g. of charcoal was added and heating was continued for an additional 15 minutes. The hot reaction mixture was then filtered through diatomite (Celite) in a preheated funnel. The filtrate became cloudy as soon as it began to cool, and it was refrigerated overnight. The resulting semi-solid mass was filtered under reduced pressure for 4 hours in order to remove the solvent. The filter cake thus obtained was slurried with about an equal volume of anhydrous ethyl acetate and the slurry was filtered. The filter cake was washed with sufiicient ethyl acetate to remove all color. The white, crystalline 1-(2-thenyl)-2-diethylaminoethyl diphenylacetate hydrochloride, after being dried overnight at 37 C. and for one hour in an oven at 60 C., had a melting point of 138 to 140 C. 100 g. of the compound was dissolved in 2.5 l. of water, and the solution was made basic (about pH 9) with 40% aqueous sodium hydroxide. The mixture was then extracted with ether. The ether extract was washed three times with water, dried over anhydrous potassium carbonate, and the ether was evaporated. 1-(2-thenyl)-2-diethylaminoethyl diphenylacetate was thus obtained as the free base.

Example 3.Preparati0n of 1-(2-Thenyl)-2-Di0ctyl Y aminoethyl Diphenylacetate Hydrochloride PART A.'PREPARATION OF 1- (2-THENYL) -2- DIOCTYLALHNOETHANOL Following the procedure of Example 1, Part A, but

substituting N-(2,3-epoxypropyl)dioctylamine for N-(2,3-

ep oxypropyl) diethylamine, 1- (Z-thenyl) -2-dioctylaminoethanol was prepared.

PART B-P'REPAR'ATION OF l-(2-THENYL)-2-DIOCTYL- AIvI-INOETHYL DIPHENYIACETATE HYDROCHLORIDE Following the procedure of Example 1, Part B, but' substituting 1-(Z-thenyl)-2-dioctylaminoethanol for 1-(2- thenyl)-2-diethylaminoethanol, 1-(2 thenyl) 2 dioctylaminoethyl diphenylacetate hydrochloride was prepared.

Example 4.Preparati0n of 1-(S-Chloro-Z-Thenyl)Z-Diethylaminoethyl Diphenylacetate Hydrochloride PART A.PREP'ARATION OF 1-(5-CHLORO-2-THENYL). 2-DHETHYLAM1N0ETHAN0I1 Following the procedure of Example 1, Part A, but substituting 2,5-dichlorothiophene for thiophene, 1-(5- chloro-2-thenyl)-2-diethylaminoethano1 was prepared.

PART B.PREPARATION OF 1-(5-CHLORO-2-THENYL) .2-

DIETHYLAMINOETHYL DIPHENYLAOEEEATE HYDRO- CHLORIDE Following the procedure of Example 1, Part B, but substituting l-(5-chloro-2-thenyl)-2-diethylaminoethanol for 1-(2-thenyl)-2-diethylaminoethanol, 1-(5-chloro-2- thenyl)-2-diethylaminoethyl diphenylacetate hydrochloride was prepared.

Example 6.Preparation of I-(Z-Thenyl)-2-(4-Propylpiperidin)Ethyl Diphenylacezate Hydrochloride PART A.PREPARATION OF '1- Z-THE NYL) 2 (4- PROPYLPIPERJZDINO ETHANOL Following the procedure of Example 1, Part A, but substituting N- (2,3-epoxypropyl)4-propylpiperidine for N- (2,3-epoxypropyl)diethylarnine, 1-(2-thenyl) 2 (4- propylpiperidino)ethanol was prepared.

PART B.-PREPARATION OF l-(2-TEIEN'YL)-2-(4-PRO- PYLPIPERLDINO -ETHYL DIPHENYLACETATE HY- DROCHLORIDE Following the procedure of Example 1, Part B, but

substituting 1-(Z-thcnyl)2-(4-propylpiperidino)ethanol for I-(Z-thenyl)2-diethylaminoethanol, 1-(2-thenyl)-2- (4-propylpiperidino)ethyl diphenylacetate hydrochloride was prepared.

Example 7.Preparation of I-(Z-Thenyl) 2-Hexamethyleneiminoethyl Diphenylacetate Hydrochloride PART A.PREPARATION OF 1-(2-THENYL)-2- HEXADLETHYLENEMINOETHANOL Following the procedure of Example 1, Part A, but substituting N-(2,3-epoxypropyl)hexamethyleneimine for N- (2,3-epoxypropyl) diethylamine, 1- (Z-thenyl) 2-hexamethyleneiminoethanol was prepared.

PART B.'PREPARATION OF 1-(2-THENYL)-2-HEXA- METHYLENEIMINO DIPHENYIJACETATE HYDRO- CHLORIDE Following the procedure of Example 1, Part B, but substituting 1-(2-thenyl) 2 hexamethyleneiminoethanol for 1-(2-thenyl)2-diethylaminoethanol, 1-(2-thenyl)-2- hexamethyleneiminoethyl diphenylacetate hydrochloride was prepared.

Example 8.Preparation of 1-(Z-Thenyl)2-Morpholinoethyl Diphenylacetate Hydrochloride PART A.-PREPARATION OF 1-(2-THENYL)2- MORPHOLINOETHANOL Following the procedure of Example 1, Part A, but substituting N-(2,3-epoxypropyl)morpholine for N-(2,3- epoxypropyl) diethylamine, l-(2-thenyl) 2 morpholinoethanol was prepared.

PART B.-PREPARATION 0F 1-(2-THENYL)-2-\IORPH- OLINOETHYL DIPHENYLACEDATE HYDROCHLORIDE Following the procedure of Example 1, Part B, but substituting 1-(2-thenyl)-2-morpholinoethanol for 1-(2- thenyl) 2-diethylarninoethanol, 1-(2-thenyl) 2 morpholinoethyl diphenylacetate hydrochloride was prepared.

hIORPHOLINOETHYL DIPHENYLACETATE HYDRO- CHLORIDE Following the procedure of Example 1, Part B, but

6 substituting 1-(2-thenyl)2-thiamorpholinoethanol for 1- (Z-thenyl)2-diethylaminoethanol, l-(2-thenyl) 2 thiamorpholinoethyl diphenylacetate hydrochloride was prepared.

Example 10.Preparation of I-(Z-Thenyl)2-(4-Methylpiperazino)Ezhyl Diphenylacetate Hydrochloride PART A.PREPARATION OF 1-(2-THENYL)-2-(4l\IE-TH- YLPIPERAZINO) ETHANOL Following the procedure of Example 1, Part A, but substituting N-(2,3-epoxypropyl)4-methylpiperazine for N (2,3'epoxypropyl)diethylamine, 1-(2-thenyl) 2 (4- methylpiperazino)ethanol was prepared.

PART B.PREPARATION OF I(2THENYL)-2(4-I\HETH- YLPIPERAZINO)ETHYL DIPHENYLNCETATE HY- DROCHLORIDE Following the procedure of Example 1, Part B, but

substituting 1- (Z-thenyl) 2 (4-rnethylpiperazino ethanol for l-(2-thenyl)2-diethylaminoethanol, 1-(2-thenyl)-2- (4-rnethylpiperazino)ethyl diphenylacetate hydrochloride was prepared.

Example 11 Ten thousand (10,000) scored tablets for oral use, each containing 25 mg. of 1-(2-thenyl)2-diethylaminoethyl diphenylacetate hydrochloride, are prepared from the following types and amounts of ingredients:

1-(2-thenyl)-2 diethylaminoethyl diphenylacetate hydrochloride 250 Starch, U.S.P 170 Talc, U.S.P 130 Lactose, U.S.P- 2600 Sucrose powder, U.S.P 37 Calcium stearafe 19.5

The finely powdered lactose and sucrose are mixed well and the mixture is granulated with 10% starch paste. The wet mass is forced through an 8-mesh screen, dried at F. in a forced-air oven, and then put through a l6-mesh screen. The remainder of the ingredients, in fine powder form, are mixed well and then mixed with the dried lactose granules. The final mixture is then compressed into tablets of the proper weight.

We claim:

1. The compound selected from the group consisting of: (1) free bases having the following structural formula wherein X is a halogen atom having an atomic weight between 35 and 80, n is an integer from 0 to 1, R and R taken separately represent lower-alkyl, and R and R taken together with N represent saturated hetero cycles of from 5 to 7 atoms in the ring selected from the group consisting of pyrrolidino, 2,2-dimethylpyrro1idino, piperidino, 4-propylpiperidino, hexamethyleneirnino, Z-methylhexarnethyleneimino, morpholino, Z-methylmorpholino, thiamorpholino, and 4-methylpiperazino, and (2) acid addition salts thereof.

2. Compound selected from the group consisting of: 1) l-(Z-thenyl)2-di-lower-alkylarninoethyl diphenylacetate and (2) acid addition salts thereof.

3. 1-(2-thenyl) 2 diethylaminoethyl diphenylacetate hydrochloride.

4. 1-(2-theny1)2-diethylaminoethyl diphenylacetate.

5. The process for preparing compounds having the following structural formula:

1.; wherein R and R are as defined above with Z-thienyllithium having the formula wherein X and n are as defined above.

6. The process according to claim 5 wherein N-(2,3- epoxypropyl)-di-lower-alkylarnine is reacted with Z-thienyllithium to produce 1-(2-thenyl)-2-di-lower-alkylaminoethanol.

7. Process according to claim 6 wherein N-(2,3-epoxypropyl)diethylamine is reacted with Z-thienyllithium to produce 1-(2-thenyl)-2-diethylaminoethanol.

References Cited in the file of this patent UNITED STATES PATENTS Blicke Feb. 21, 1956 OTHER REFERENCES Forneau et al.: Bull. Soc. Chim 4, 45, pp. 11721189 (1929).

Richter: Organic Chemistry, vol. 111, Heterocyclic Compounds, P. Blakistons Son & Co., Philadelphia, Pa. (1923 pp. 21-22.

Cook et al.: Journal of the Chemical Society (1936), pp. 71-72.

Kaye et al.: Journal of the American Chemical Society, vol. 74, pp. 3676-6679 (1952).

Patent No. 3,122,561 February 25, 1964 Louis F. Cason et all;

It is hereby certified that err ent requiring correction and that th corrected belo" or appears in the above numbered pate said Letters Patent should read as Column 5, lines 41 and 42, for "HEXAMETHYLENEIMINO" read HEXAMETHYLENEIMINOETHYL column 7, lines 23 and 24, for

"morpholino, thiamorpholins" read morpholino, Z-methyI- morphol ino, thiamorpholino Signed and sealed this 20th day of October 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. THE COMPOUND SELECTED FROM THE GROUP CONSISTING OF: (1) FREE BASES HAVING THE FOLLOWING STRUCTURAL FORMULA 